This invention relates generally to direct support type railroad trackwork frog assemblies such as the known frog assembly disclosed in co-pending application for U.S. Letters Patent Ser. No. 081516,504, filed Aug. 17, 1995 now U.S. Pat. No. 5,496,004 and assigned to the assignee of this application.
It has been observed in connection with known railroad trackwork frog assemblies that the threaded bolt and nut fasteners utilized to join the assembly wing rails and the assembly core frog casting into a unitary structure often become loosened as a result of assembly use and also as a result of thermal expansion and contraction. Conventional nut-locking features combined with the threaded fasteners do not function satisfactorily and as a result periodic maintenance re-tightening of the assembly fasteners is frequently required during the service life of each such assembly.
Also, it has been common practice to manufacture and machine a different size of assembly core frog casting for each frog assembly having a different size of wing rail components. By way of example, in instances where frog assemblies were offered for trackwork applications involving six different sizes of A.R.E.A. standard trackwork rail sections it has been the practice to design, cast, and machine at least six different sizes (configurations) of a core frog casting. Such practice has resulted in substantial unnecessary pattern making, machining, inventorying, and maintenance costs being incurred by the manufacturer of the frog assemblies.
We have discovered that the maintenance and manufacturing shortcomings associated with the prior art approaches to design and construction of rigid railbound frog assemblies may be overcome through a practice of our invention.
Other objects and advantages of our invention will become apparent from consideration of the drawings and detailed descriptive materials which follows.